Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Anthony Absalom, University of Groeningen
- Second opponent: Professor Lone Nikolajsen, Aarhus University
- Third member and chair of the evaluation committee: Professor Syed Sajid Hussain Kazmi, University of Oslo
Chair of the Defence
Professor Emeritus Ulf Kongsgaard, University of Oslo
Principal Supervisor
Professor Emeritus Johan Ræder, Universitetet i Oslo
Summary
Obesity presents challenges in dosing anaesthetic agents, as body composition and pharmacokinetics differ from those in normal-weight patients.
This thesis is focused on the pharmacokinetics of propofol in patients with severe obesity and on exploring novel means of pharmacological monitoring in this population.
A three-compartment population pharmacokinetic model was developed using 474 serum samples from 69 surgical patients. The study included both normal-weight and severely obese patients, with body mass indices exceeding 50 kg/m², making the model applicable to adult patients of all body sizes.
In computer simulations, the model demonstrated improved precision compared with currently used models.
A novel device utilising ion mobility spectrometry technology to measure propofol concentrations in breath during general anaesthesia was evaluated to determine whether it could further refine dosing in obese patients.
With the device, breath propofol concentrations were analysed and displayed in near real-time during general anaesthesia, in 29 normal-weight and severely obese patients. A weak correlation was observed between breath and plasma concentrations of propofol. The device performed best during pseudo-stable phases of anaesthesia, with a five-minute delay identified between plasma and breath concentrations under these conditions.
These findings may contribute to safer and more precise anaesthesia for patients with obesity -a population underrepresented in research.
Additional information
Contact the research support staff.